For a number of years, articles of footwear and various items of clothing have been sold with decorative arrays of light sources such as light emitting diodes (LEDs). This has been particularly popular in children's footwear where the LEDs are arranged to complement other design elements of the shoe, including cartoon characters and the like.
LEDs are used in a variety of ways in children's shoes to create different visual effects. For example, one or more LEDs may be mounted at one end of a clear polymer strip formed with etchings or other designs on its inner and/or outer surfaces. The polymer strip is effective to transmit the light emitted by the LED from one end toward the other, and the etchings or other surface markings on the strip reflect the light in a desired pattern. See U.S. Pat. No. 5,857,273.
Other visual effects are obtained using LEDs of different colors and/or varying how the LEDs are illuminated. LEDs are currently available in red, green, blue and white. Designers often employ LEDs of one or more colors arranged in designs located on the upper of the shoe or its outsole to obtain a desired effect. More recently, color mixing LEDs have been proposed in which primary color chips of red, green and blue are arranged side-by-side in a housing and selectively illuminated for a predetermined time period to produce other colors. For example, combining red and green light produces purple, and orange light is produced by combining red and green. See U.S. Pat. No. 6,764,193 and U.S. Patent Application Publication US 2003/0231513.
With respect to illumination of LEDs in shoes and other articles of clothing, a typical design includes a module having a battery, a switch, and, conventionally, an integrated circuit (“IC”). The IC is connected by wires to LEDs positioned along the outsole, upper or tongue of the shoe, or at a desired location on another article of clothing. The IC is effective to turn on and off the LEDs, often in a flashing sequence, to enhance the visual effect and draw attention to the shoe or other article of clothing. In many designs, the IC is enabled by a switch operative in response to motion or pressure.